Issue 4353 - Remove deprecated __proto__ syntax

lib/subscriptionClasses.js

Index: lib/subscriptionClasses.js
diff --git a/lib/subscriptionClasses.js b/lib/subscriptionClasses.js
index f559cb3937f42a8caff29135c7799e90c598183f..a154e7fb603ed1bac727349b6b9b9e13c2654996 100644
--- a/lib/subscriptionClasses.js
+++ b/lib/subscriptionClasses.js
@@ -21,6 +21,7 @@
 
 let {ActiveFilter, BlockingFilter, WhitelistFilter, ElemHideBase} = require("filterClasses");
 let {FilterNotifier} = require("filterNotifier");
+let {desc, extend} = require("coreUtils");
 
 /**
  * Abstract base class for filter subscriptions
@@ -229,10 +230,7 @@ function SpecialSubscription(url, title)
 }
 exports.SpecialSubscription = SpecialSubscription;
 
-SpecialSubscription.prototype =
-{
-  __proto__: Subscription.prototype,
-
+SpecialSubscription.prototype = extend(Subscription, {
   /**
    * Filter types that should be added to this subscription by default
    * (entries should correspond to keys in SpecialSubscription.defaultsMap).
@@ -272,14 +270,13 @@ SpecialSubscription.prototype =
     if (this._lastDownload)
       buffer.push("lastDownload=" + this._lastDownload);
   }
-};
+});
 
-SpecialSubscription.defaultsMap = {
-  __proto__: null,
+SpecialSubscription.defaultsMap = Object.create(null, desc({
   "whitelist": WhitelistFilter,
   "blocking": BlockingFilter,
   "elemhide": ElemHideBase
-};
+}));
 
 /**
  * Creates a new user-defined filter group.
@@ -327,10 +324,7 @@ function RegularSubscription(url, title)
 }
 exports.RegularSubscription = RegularSubscription;
 
-RegularSubscription.prototype =
-{
-  __proto__: Subscription.prototype,
-
+RegularSubscription.prototype = extend(Subscription, {
   _homepage: null,
   _lastDownload: 0,
 
@@ -383,7 +377,7 @@ RegularSubscription.prototype =
     if (this._lastDownload)
       buffer.push("lastDownload=" + this._lastDownload);
   }
-};
+});
 
 /**
  * Class for filter subscriptions updated externally (by other extension)
@@ -398,10 +392,7 @@ function ExternalSubscription(url, title)
 }
 exports.ExternalSubscription = ExternalSubscription;
 
-ExternalSubscription.prototype =
-{
-  __proto__: RegularSubscription.prototype,
-
+ExternalSubscription.prototype = extend(RegularSubscription, {
   /**
    * See Subscription.serialize()
    */
@@ -409,7 +400,7 @@ ExternalSubscription.prototype =
   {
     throw new Error("Unexpected call, external subscriptions should not be serialized");
   }
-};
+});
 
 /**
  * Class for filter subscriptions updated externally (by other extension)
@@ -424,10 +415,7 @@ function DownloadableSubscription(url, title)
 }
 exports.DownloadableSubscription = DownloadableSubscription;
 
-DownloadableSubscription.prototype =
-{
-  __proto__: RegularSubscription.prototype,
-
+DownloadableSubscription.prototype = extend(RegularSubscription, {
   _downloadStatus: null,
   _lastCheck: 0,
   _errors: 0,
@@ -549,4 +537,4 @@ DownloadableSubscription.prototype =
     if (this.downloadCount)
       buffer.push("downloadCount=" + this.downloadCount);
   }
-};
+});